Steam economizing system



Sept. 9, 1952 P, SPENCE 2,609,990

STEAM ECONOMIZING SYSTEM Filed 0G13. 1l, 1949 l 2 SHEETS--SHEET 2 BY Z I Arran/vers V Patented Sept. 9, 1952 STEAM ECoNoMizING SYSTEM Paulsen Spence, Baton Rouge, La., assignor to Spence Engineering Company, Inc., Walden, N. Y., a corporation of Newr York Application october 11, 1949, serial No. 120,705

My invention relates to economizing means, as for use in a steam-operated system in which a high-pressure-operated means is to be operated relatively intermittently and in Which a lowpressure-operated means is to` be operated relatively continuously.

It is an object of the invention to provide an improved system of the character indicated.

It is another object to provide an improved means for maintaining continuous operation of low-pressure-operated means in spite of intermittent operation of high-pressure-operated means from the same boiler plant.

It is a specific object to provide means whereby a low-pressure-operated means may be operated by exhaust steam from high-pressure-operated means as long as the high-pressure-operated means is operative, but in which a regulated ilow of reduced-pressure steam may be automatically supplied to said low-pressure-operated `means during periods in which the high-pressure-operated means is not functioning or in which the quantity of exhaust steam supplied thereby is insuicient.

Other objects and various further features of the invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show,` for illustrative purposes only, preferred forms of the invention:

Fig. 1 is a simplified layout schematically showing a system to which my steam-economizing system has been applied; and

Figs. 2 `and 3 schematically show alternative forms of the invention.

Briefly stated, my invention in a preferred form contemplates application to a steam-operated plant in which high-pressure-operated means, such as a steam engine to run a juice extractor, is operated intermittently and in which low-pressure-operated means, such as evaporating heaters, are to be run more or less continuously. The` low-pressure-operated means for heaters may beconnected in the exhaust line from the steam engine, and damper means further down the exhaust line may assure the needed low-pressure steam in the heaters as long as the engine is operating. During periods when the steam engine is not operating or in which the `back pressure is insuicient for the heaters, I provide a by-pass. connection between the highpressure side of the steam engine and the heaters, and this by-pass connection may include `pressure-reducing means to provide the desired 13 Claims.

low-pressure steam for the heaters. In order that the by-passed steam shall not be wasted, I provide means for automatically closing the damper means during idle periods for the steam engine; and the pressure-reducing system may be interlocked with the damper means, or with the means forcontrolling the damper means, so as not to by-pass steam until the damper means has been closed. The damper means may be closed by pressure-responsive means responsive to back pressure from the steam engine, and the pressure-reducing system may be pilot controlled. In one form to be described, the pilot-controlled reducing valve is interconnected with the pressure-responsive means for controlling the damper; in another form, the damper is mechanically interlocked with the pilot control for the pressure-reducing system; and, in the third `form, the pilot control is electrically interlocked with the damper.

Referring to Fig. 1 of the drawing, my invention is shown in application to a steam-operated plant such as a cane-sugar mill. The plant may include means (not shown) for supplying highpressure steam in an inlet line 5 to a steam engine 6, which engine 6 may be for operation of a juice extractor or the like, for relatively short intermittent periods. The exhaust steam from the engine 6 may pass through an outlet 'l to a stack 8. The mill may further include low-pressure-operated means, such as heaters for an evaporating system, to be run more or less continuously; and the heaters (not shown) may be supplied via a line 9, connected to exhaust line `I for the engine 6. In order to assure suicient low pressure for operation of the heaters via line 9, a damper in the form of a lever-operated damper valve l0 may be interposed between the line 9 and the exhaust stack 8.

In accordance with a feature of the invention, the damper valve I0 may be operated to assure continuous supply of low-pressure steam to the heaters in line 9, even during shut-down periods for the engine 6. Such controlling means may include pressure-responsive means Il connected in the exhaust line 'l or in the heater line 9 (as shown at 9'), and in the form shown the presactuator I2 to be driven upwardly, and thus to permit a lowering of the lever I4 for the damper Ii), in order to close the damper III. Upon a rise in pressure in the line 9, as when the engine 6 is again operated, the pressure-responsive means II will be understood to reverse the operation of the actuator I2, in order once more to open the damper I0.

In accordance with a further feature of the invention, I provide a means for by-passing the steam from the high-pressure line to the heater line S whenever the heater-supply pressure has dropped to a given minimum value, which may be the low pressure at which the damper IB is closed. The by-passconnection may include pressure-reducing means which preferably supplies steam at a sufficiently low pressure as not'to open the damper It. The pressure-reducing` means may include a main valve I5 having an inlet line It connected to the high-pressure line 5 and an outlet line IInconnected to the exhaust line 'I of the engine oi the damper It. The pressure-reducing means maybe pilot controlled, as disclosed more speciiically in my Patent 1,995,949, dated March 26, 1935. .The main valve l5 may be diaphragm-actuated, andpressures over the diaphragm may be derived from a line i8 connected to the high-pressure side of the valve i 5 and including a pressure-responsive -pilot I9. rEhe pilot may derive its control'pressures from a line 2li connected to the'low-pressureend oi the lay-pass connection, as at the pipe ITI; and the low-pressure side of the pilot I9 may'be connected by line 2l tothe diaphragm, andby a'b'leed connection 22 to the low-pressure side/of the main valve I5.

In the form shown, I employ 'afurther'pressure-operated pilot '23 inseries'with'thelpilct I9 in order to control the Orl-off operation vof the pressure-reducing by-pass connection. YRegulating-valve control by meansof apluralityof'pilots in series is shown and described in' detail in'my Patent 1,987,1332. The pressure-responsivemeans ci pilot 23 may be a water-actuated diaphragm connected, as by line`2`4, to one ofthe ends of the double-acting actuator I2. The connectionY of pilot 23 to the actuator'li is preferablysuchv that the pilot 23 will b'efo'pened upon "a supply of damper-closing water pressure to theactuator i2. Only upon loss of such closingpressurea as when 'the' steam engine iis againcperated (so as to open the damperY Iii)` wiilthesprings 25 or" pilot 23 be eifectiveto close oiif'tlie''Ioyepass connection.

In Fig. 2, I showl an alternative'embodiment of my invention for substantiallythe same use and application as'has been' de-scribed'above in connection with Fig. l. In Fig. 2,v however, the opening and closing or" the by-'pass connection is effected by a mechanical connection between a pilot valve 3i? and the damper IIJ. (Such mechanical connection may include a-link SI between the lever iai for the damper valve III and arocker 32 for actuating the pilot 36. It-'will-bevunderstood that, Whenever the pressure-responsive means VI I-l2 demands a closure of damper III, as after the `engine Sl is shut down, thefleveritl 'will be displaced vdownwardlyand at the same time-the pilot 'i will ne openedin order to'lopen the pressure-reducing ley-pass connection and thus to maintain continued' supply ofv low-pressure steam, as needed,v tothe evaporator heaters.

In `Fig.3, I rshow another alternative arrangement according to the invention. -In Fig. 3,"however,'I employ electrically controlled interlocks for closing and opening the pressure-reducing bypass connection in accordance with the operation and shutdown of the engine 6. In Fig. 3, I employ a solenoid-operated pilot valve 35 in series connection with the pilot I9 of the pressure-reducing means, and a switch 36 may be in electrical-controlling relation with the solenoid of valve 35. In the form shown, the switch 35 is positioned to be actuated when the damper lever I4 reaches a downward position, whichV may be representative of a closed damper. It will then be understood that only upon closure of the damper may the by-pass connection IB--II be opened to supply reduced pressure to the heaters.

When the engine ii is started again, the baci;

Vpressure will rise so as to operate the actuator I2 and thus to open the damper I0. This lopening of the damper Iii will be evidenced by a lifting of the lever Ill and, as soon as the lever I4 is lifted from its bottom position, the switch 36 may be eiective to close oilc the Icy-pass connection IG-I i.

It will be seen that I have described a relatively simple system for assuringthe economical supply oi low-pressure steam to a continuously operated low-pressure system, even during extended sh'ut-down periods for ahigh-pressureoperated means connected to the same steamsupply system. My econcmizing system may be adjusted toV operate only when the damper is closed and therefore to utilize all theby-passed steam.

While I have described my invention inV considerable detail for the preferred forms shown, it will be understood that modications may be made within the scope of the invention as defined in the appended claims.

' I claim:

l. `In a steam-economizing system Aof the charactor indicated, high-pressure-operated means to be intermittently operated,-low-pressure-operated means to be more continuously operated, .said high-pressure-operated'means including an inlet for high-pressure steam and an exhaust outlet, a damper in said exhaust outlet, said low-pressureoperated means being connected to said exhaust outlet between said damper and said high-.pressure-operatedmeans, said damper including preslsteam to said low-pressure-operatedmeans upon `a closure of' said damper and forV cutting o said by-pass connection upon an opening of said damper.

2. In asteam-economizing system of the character indicated, high-pressure-operated means including aninlet for steam at relatively high pressure and an exhaust outlet, a damper in said exhaust outlet, `low-pressure'-operated means connected to .said exhaust outlet between Ysaid high-pressure-operated means and Vsaid damper, pressure-responsive-damper-actuating means in .said'exhaust outlet and connected'to said damper to lcloseisaid"danf1per upon a drop in -back pressure below 'a :given value, a Vpressure-reducing Icy-pass connection between the .night-pressure inlet toi said:high-pressure-operated means and said rlow-pressure'-operated means,said.bypass connection includingV onu-ofi controllmeans connected to said damper-actuating means for opening said by-pass connection upon suiiicient drop in back pressure to close said damper and for closing said by-pass connection upon a rise in back pressure suiiicient to open said damper.

3. A system according to claim 2, in which said means opening said by-pass connection is a pressure-operated Valve operative upon operation of said pressure-responsive means.

4. A system according to claim 2, in which said means opening said by-p-ass connection is a valve mechanically interconnected with said damper to open said valve upon closure of said damper.

5. A system according to claim 2, in which said means opening said by-pass connection is an electrically-operated valve electrically connected to a switch operated upon closure of said damper, whereby said by-pass connection may not be opened until said damper has been closed.

6. In a steam-economizing system of the character indicated, high-pressure-operated means including an inlet for high-pressure steam and an exhaust outlet, a damper in said exhaust outlet, low-pressure-operated means connected to said exhaust outlet between said high-'pressure operated means and said damper, pressure-responsive double-acting actuating means for said damper and connected to said exhaust outlet to close said damper upon a drop in back pressure below a given value, a by-pass connection from the high-pressure inlet side of said high-pres- 9 sure-operated means to said low-pressure-operated means, said by-pass connection including a pressure-operated valve connected to one side of said double-acting pressure-responsive means, said last-mentioned connection being such that said by-pass connection is opened upon closure of said damper and closed upon opening of said damper. i

7 A system according to claim 6 in which said by-pass connection includes pressure-reducing means providing a reduced pressure below said given value, whereby said damper may remain closed as long as said by-pass connection is eiTective to supply by-passed steam.

8. In a steam-economizing system of the character indicated, high-pressure-operated means including an inlet for high-pressure steam and an exhaust outlet, a damper in said exhaust outlet, low-pressure-operated means connected for supply from said exhaust outlet at a point between said damper and said high-pressure operating means, a by-pass connection between said high-pressure inlet and said low-pressure-operated means, said by-pass connection including a pilot-controlled regulating valve, pressure-responsive means responsive to back pressure and connected to close said damper upon a drop in back pressure below a given value, and pilotvalve means in series connection with the pilot of said regulating valve and eiective to operate said regulating valve upon a closing of said damper.

9. In a steam-economizing system of the character indicated, steam-operated means including an inlet and an exhaust outlet, a damper in said exhaust outlet, heater means connected to said steam-operated exhaust outlet between said means and said damper, pressure-responsive damper-actuating means in said exhaust outlet between said steam-operated means and said damperiand connected to said damper to close heater means, said by-pass connection including on-off control means responsive to exhaust pressure upstream from said damper to open said by-pass connection upon a suflicient drop in exhaust pressure to effect closure of said damper, said control means being further effective to close said by-pass connection upon a sugcient rise in exhaust pressure to effect an opening of said damper, whereby live steam may never be vented by said damper.

10. In a steam-economizing system of the character indicated, steam-operated means to be operated intermittently and including an inlet for relatively high-pressure steam and an exhaust outlet, damper means for said exhaust outlet and including pressure-responsive direct-actuating means therefor, auxiliary means to be operated by steam at relativelylow pressure, said auxiliary means being connected to said exhaust outlet between said rst-mentioned means and said damper means, said pressure-responsive direct-actuating means being connected for response to a drop in pressure at the exhaust side of said rst-mentioned means and effective to close said damper means, pressure-reducing means between the high-pressure side of said first-mentioned means and said auxiliary means, and on-oi control means for said pressurereducing means and directly connected for operation by said direct-actuating means,`whereby said pressure-responsive direct-actuating means may assuredly enable said pressure-reducing means upon a suiicient drop in pressure to close said damper means, and whereby said pressurereducing means may be effectively shut off upon a suicient rise in pressure to open said damper means, so that live steam may never be vented by said damper means.

11. An economizing system according to claim 10, in which said cn-oi control means includes biassing means biassing said control means against an enabling of said pressure-reducing means until attainment of a sulciently low exhaust-outlet pressure to assure closure of said damper means, whereby said damper means may not begin to openl until after said pressure-reducing means has been cut off.

12. An economizing system according to claim l1, in which said control means is a pressureresponsive control valve, and in which said biassing means is a spring stressed against a pressure-responsive element of said control valve.

13. An economizing system according to claim l0, in which said on-oif control means is connected to enable said pressure-reducing means only during maintenance of a sufficiently low exhaust-outlet pressure to assure closure of said damper means, whereby said damper means may not begin to open until after said pressure-reducing means has been cut off.

PAULSEN SPENCE.

REFERENCES CITED The following references are of record in the file of this patent:

` UNITED STATES PATENTS Number Name Date 802,441 Bellows Oct. 24, 1905 `1,154,210 Santry Sept. 21, 1915 FOREIGN PATENTS Number Country Date 689,463 France May 27, 1930 

